Enhancement of heat transfer at pool boiling on surfaces with silicon oxide nanowires

Abstract

Abstract. The boiling heat transfer on the local heaters with microstructured and nanomodified surfaces was studied. As nanomodified surfaces we used copper ones where the microropes of silicon oxide nanowires were grown. The aging of the nanomodified surface was observed after first series of experiments. It was shown that both finning and nanostructuring of the surface result in increase of heat transfer. The heat flux density of 1400 W/cm 2 was reached.

Effect of the distance between the micro/nanostructures on pool boiling heat transfer with water on a copper heater

“…However, the small micropores were largely destroyed, and the contact angle increased several times. The data obtained confirm the result from [7] that microropes are mechanically unstable and easily break down during boiling. Figure 4 shows SEM images of an array of micrococoons of silicon oxide nanowires on the surface of a copper heater with a tungsten barrier layer for sample # 2 before (Figure 4a) and after the experiment (Figure 4c).…”

“…The arrays of micrococoons from SiOx nanowires were synthesized by the gas-jet electron beam plasma chemical vapor deposition method on a tin catalyst [5][6][7]. Hydrogen, a 5% mixture of monosilane in argon, and oxygen were used as processing gases.…”

“…In this case, the catalyst particle may have direct contact with the substrate, as a result of which the adhesion to the surface increases. It was previously shown that the arrays of microstructures made of SiOx nanowires, consisting of microropes and micrococoons, lead to an increase in heat transfer during boiling [7]. However, the latter are more stable and less susceptible to destruction.…”

Effect of fluoropolymer spots on pool boiling heat transfer

“…First, tin particles were deposited on the surface, previously coated with tungsten, which acted as a growth catalyst. The synthesis of silicon oxide nanowires was carried out by the gas-jet electron beam plasma chemical vapor deposition method on particles of the tin catalyst [7][8][9][10]. As a result, an array of micrococoons was formed on the surface.…”

“…In this work, it was assumed to create an array of micrococoons -tin catalyst particles placed on the surface and overgrown from all sides with SiOx nanowires. Such structures have shown themselves to be the most stable to fracture during boiling since they have better adhesion in comparison with other investigated structures [9], which is an important factor for determining the practical applicability of the technology.…”